1. Field of the Invention
This invention relates generally to internal combustion engines and, more particularly, to a fuel system utilizing primary and secondary carburetors, the latter supplying the former, and a single source of fuel selectively supplying either carburetor.
2. Prior Art
As is well known, the rising costs of gasoline and the periodic shortages thereof inspired the search for alternate methods of powering vehicles. One such known alternate method is the substitution of alcohol for gasoline. Alcohol is significantly less expensive than gasoline and is readily available from a number of sources. Vehicles presently exist which are powered by alcohol.
It is also well known that fuel in a vapor or gaseous state may be more efficiently converted to energy than when in a liquid state. As a result, vehicles have been constructed which are powered by vapor or gaseous fuel. Such systems, however, have certain disadvantages. First, the availability of gaseous or vapor fuel is limited and therefore it is doubtful that such vehicles will gain wide acceptance. Second, such vehicles require an on-board high-pressure storage tank. Third, while it is true that vapor fuels are more efficient, engines utilizing such fuels are more difficult to start than liquid fuel engines since liquid fuel systems generally provide a richer air/fuel mixture for combustion.